Patent GB-1097071-A (GB)
Title: Metal sawing machine
Inventor: SHERRIFF ARTHUR IRVING
IPC: B23D51/04
Filed: 1963-07-24
Abstract: 1,097,071. Sawing. BRIGGS & SHERRIFF Ltd. Oct. 26,1964 [July 24,1963], No. 29241/63. Heading B5L. A sawing machine having a vice or collet 2 for securing a length of bar stock W from which sections are to be cut, and a saw 10 mounted for movement transversely to the axis of the bar stock comprises, in combination, means 14 for feeding a length of bar stock through the open vice or collet, means for opening and closing the vice or collet, means for moving the saw relative to the vice or collet for cutting a length of bar stock clamped by the latter, and means to control all the aforesaid means automatically, in timed relationship, to cut off successive sections from the bar stock. The saw may be of the rotary type but is of the reciprocating type in the preferred embodiment. As described, the saw 10 is carried by a frame 9 having a pair of guideways 6 slidable in sleeves 7 on a stem 8, the frame being reciprocated by a link 11 driven from an electric motor and the sleeves being formed in an arm 5 mounted on a pivot (not shown). The pivot is on a post upstanding from a bed 1 on which is the vice 2 which may have both jaws movable or, as shown, have a fixed jaw 3 and a movable jaw 4. A support 12 extends from the vice and has channels for receiving the wheels 13 of a carriage 14 which has a fixed wall 17 and a gripper 19 movable about a pivot 18 by a screw 20 to clamp the workpiece against the fixed wall.- A further gripper carried by an arm mounted on a horizontal pivot can be urged by a screw 23 to clamp the workpiece against the carriage. The carriage is movable along the support by a chain which has its ends connected to the carriage and is entrained over a sprocket below the rear end of the support and a sprocket 26, Fig. 3, in a casing below the forward end of the support. The sprocket 26 is mounted on a shaft 28 which can be connected by a clutch 30 to a sprocket 31 connected by a chain 32, Fig. 4, to a sprocket driven by a worm-drive 35, 36 from a motor 29. The clutch is engaged or disengaged by rocking of a lever 44 movable by a cam 46 on a cam-shaft 49 which also carries cams 50, 51, 52 and 53 and a gear 55 meshing with a gear 56 on a countershaft 57 connected by a worm-and-wheel arrangement 58, 59 to a motor 54, whereby the cam-shaft is rotated. The cam 50 engages one arm 64 of a bell-crank lever 63 mounted on a countershaft 62, the other arm 66 being connected by a linkage to the saw arm 5 for raising and lowering the saw. The cam 53 engages an.arm of a bell-crank lever 68, the other arm 71 of which is connected by a rod 111 to toggles 107, 108. Toggle 108 is connected to the support 12 and toggle 107 is joined to a fork-piece 105 which is mounted on a pivot 106 and embraces a rod 104 connected to the movable jaw 4 of the vice. The cams 51, 52 actuate micro-switches 74, 75 controlling, respectively, the motors 29, 54. The switches are mounted on a plate 73 which is freelymounted on the cam-shaft 49 between the cams 51, 52 and urged by a spring 76 to a position determined by a stop 77. A link 78 is disposed between the casing 25 and plate 73 and can be moved to rotate the plate and actuate the switches by a lever 79 which is freely rotatable on the countershaft 62, but is movable by a lug 80 on a collar secured to the countershaft or by an arm 82 movable about a pivot by a slide 83. The slide is movable to effect actuation of the switches so that the motor 29 is operated to control the forward feed of the carriage 14 and the length of workpiece to be cut by engagement of a projection 90, Fig. 5, on the slide 83 by a projection 89 on a control disc 39 of the clutch. The control disc has a peripheral groove and one end of a cord 86 is secured to the groove and is tensioned by a spring-urged pulley 87, Fig. 3, the cord having its other end secured to the casing. A control element 91 is disposed adjacent the clutch and is connected to a graduated dial 92; the element has an abutment 91a and, when the clutch is disengaged, the control disc is rotated by the tensioned cord 86 to a position in which the abutment 89 engages the abutment 91a; the amount of rotation of the disc 39 to effect engagement of the abutment 89 with the projection 90 on the slide 83 determines the advance of the carriage and length of workpiece to be cut. A device for setting the machine to cut a predetermined number of workpieces is provided and consists of a graduated dial 93 associated with a knob connected to a gearwheel differing by one tooth from a second gear-wheel secured to the casing, both gearwheels being freely rotatable on the cam-shaft 49. An arm secured to the cam-shaft is disposed between the gear-wheels and carries a double pinion engaging both gears. The graduated dial can be secured in a predetermined position relative to the movable gear and is moved an increment of rotation for each rotation of the cam-shaft, and hence each sawing operation, until it reaches a position in which a notch on its inner periphery receives a pin on a latch which is thereby able to move to actuate microswitches controlling the motor 54 for rotating the cam-shaft. In operation, the carriage is moved to a rearward position determined by the length of the workpiece, the clutch 30 being disengaged to permit movement of the carriage, and the workpiece is clamped by the plates 19, 22 and extends between the open jaws of the vice 2 and abuts the side of the saw blade. The dial 92 is set to the length of workpieces to be cut and the dial 93 to the number of workpieces required. A starter switch is then operated and the saw motor is started as also, because microswitch 75 is closed, is the cam-shaft motor 54. Rotation of the cam-shaft raises the saw arm and closes clutch 30 and also operates the micro-switches 74, 75 to stop motor 54 rotating the cam-shaft and start motor 29 to advance the carriage until the abutment 89 on control plate 39 engages abutment 90 to move slide 83 and rock plate 73 so that the micro-switches are again actuated to stop the motor 29 and re-start motor 54 to continue rotation of the cam-shaft. The further rotation of the cam-shaft causes the vice jaws to be closed and the saw arm 5 to be lowered. Rotation of the cam-shaft continues until abutment 80 move arm 79 to rock the plate 73 so as to stop motor 54. At the lowermost position of the saw arm, the plate 73 is again moved to cause the motor 54 to rotate the cam-shaft for another cycle unless the device 85 has been actuated to stop the machine. In other embodiments, the saw arm and vice jaw are movable by screws driven by electric motors controlled by cams.